Where can Open Baffle speakers be placed

bad idea.  this would defeat what OB speakers are all about.  Minimum of 2-3 feet suggested.

Even 2-3 feet is sub-optimal. 5' is much better; that creates the required 10ms delay between front wave and reflected rear wave arrival times at the listening position.

If you like one-dimensional soundstages....

As a long time OB owner, part of where to place them has to do with your room dimensions, but a good starting point is ~ 1/3 from the front wall. I keep mine on Harbor Freight dollys which makes it easy to move them, especially if you can't keep them out that far 24/7

hth

Oh boy, I was anticipating this response. I guess I'll have to wait for now.
Thank you all for weighting in.
Now back to considering the Focal or Dali line of speakers for an upgrade. Any thoughts on this? I've got to get to California to listen, Las Vegas as a difficult place for evaluating higher end options.
I have a room that could handle the OB speakers but I would have to take over another room in the house but that could cause major wife issues, she loves me but talk about pushing the envelop of sound :(

Take a look at Audio Note.  Designed for Japanese- and British-sized rooms.

OP, have you tried moving the  KEF LS50's into the room more.

You might be surprised, with BETTER current speaker placement, and room treatment. 

I assure you treating the room will pay higher sonic dividends, than a speaker change dollar for dollar, and speaker placement, cost nothing.

Room treatment
Speaker placement
Route and clean up the cabling if you have any...

Some of those have onboard amps, ay? There was a thread here about PC swaps.... I think that speaker has that option???
 
LOW cost.. big returns dollar for dollar..

Merry Christmas everyone...

Regards

All speakers work different in different rooms. My sapphires M3’s work very well 32” from the front wall in my room out further the bass is not as good, now I have ASR panels and bass traps in each corner of the front wall along with heavy curtains. I have a well balanced sound, good depth, width suffers due to my size of the room but I have the tweeter 24” from each side wall. The rest is so good, that I can live with that, also never ever have anything between the speakers, if so you not hearing what we work hard to pay for. My amp is on a stand between the speakers and the racks is 16’ away. Put my rack between the speakers once and I was tearing back down to move it 10 minutes later. 

Check out LSA 10 Statements at Underwood HiFi

excellent reviews and very reasonable price, especially when system firing on short wall
hth